tasks/autodetect: replace needless strdup of device_info.name with stack buffer

input_autoconfigure_connect_handler has a block that temporarily
overwrites autoconfig_handle->device_info.name with a fallback-driver
name (e.g. 'XInput Controller' / 'Standard Gamepad'), re-runs the
scan, then restores the original.  It saved the original name via

    char *name_backup = strdup(autoconfig_handle->device_info.name);

and free()d it after the restore.  Two problems with that:

  1. device_info.name is a fixed-size char[128] ivar on
     input_device_info_t (input/input_driver.h:334), not a heap
     pointer.  Heap allocation and free are unnecessary; a stack
     buffer sized from sizeof(device_info.name) does the job with
     zero allocator traffic.

  2. strdup returning NULL was not checked.  If the malloc failed,
     the subsequent strlcpy(device_info.name, name_backup, ...)
     would call strlcpy with src=NULL, which is undefined behaviour
     and on glibc / Bionic / musl will segfault inside strlen.

Fix: declare 'char name_backup[sizeof(autoconfig_handle->device_info.name)]'
on the stack right where the old strdup was, copy into it with
strlcpy, and drop the manual free / NULL-assign at the end of the
block.  No heap allocation, no OOM failure mode.

Thread-safety: unchanged.  input_autoconfigure_connect_handler runs
on the task worker thread; device_info is owned by autoconfig_handle
which is the task's state struct.  The name_backup buffer is a
short-lived local; nothing else accesses it.

Scope: this runs once per input device connection (low frequency
event), so the fix is correctness-focused, not a performance
improvement.  Same pattern as the savestate-thumbnail fixes in
93449d3 / 741ead4 (needless strdup of fixed-size char[] ivars).

Author: LibretroAdmin

tasks/task_autodetect.c

@@ -756,7 +756,18 @@ static void input_autoconfigure_connect_handler(retro_task_t *task)
           && !string_is_equal(autoconfig_handle->device_info.name,
                fallback_device_name))
       {
-         char *name_backup = strdup(autoconfig_handle->device_info.name);
+         /* Save/restore device_info.name around the fallback-name
+          * autoconfig scan.  device_info.name is a fixed-size
+          * char[128] ivar, not a heap pointer, so the previous
+          * strdup + free was unnecessary heap traffic, and carried
+          * a NULL-deref-on-OOM failure mode (strdup returning NULL
+          * was not checked before strlcpy(name, name_backup, ...)
+          * below).  A stack buffer of matching size sidesteps both
+          * issues. */
+         char name_backup[sizeof(autoconfig_handle->device_info.name)];
+
+         strlcpy(name_backup, autoconfig_handle->device_info.name,
+               sizeof(name_backup));
 
          strlcpy(autoconfig_handle->device_info.name,
                fallback_device_name,
@@ -771,9 +782,6 @@ static void input_autoconfigure_connect_handler(retro_task_t *task)
          strlcpy(autoconfig_handle->device_info.name,
                name_backup,
                sizeof(autoconfig_handle->device_info.name));
-
-         free(name_backup);
-         name_backup = NULL;
       }
    }