gfx/egl: plug configs leak on no-matching-attributes failure path in egl_init_context_common

egl_init_context_common malloc()s an EGLConfig array to pass to
_egl_choose_config, then iterates it to find a caller-accepted
config.  On the normal failure-to-find path (i == *count) the
function correctly free()s the array before returning false.

The error path immediately above it - when _egl_choose_config itself
fails or returns matched == 0 - skipped that free:

    if (!_egl_choose_config(egl->dpy, attrib_ptr,
             configs, *count, &matched) || !matched)
    {
       RARCH_ERR("[EGL] No EGL configs with appropriate attributes.\n");
       return false;    /* leaks 'configs' */
    }

The allocation can be sizeable on systems advertising many configs
(typical count 10-50, typical sizeof(EGLConfig) is a pointer), so
this is tens to hundreds of bytes per failed init attempt.  The
leak is persistent across repeated attempts - if a GL driver
reinits after a display mode change and this path trips each time,
it accumulates.

Fix: add the free(configs) before the return false, matching the
successful-no-candidate path further down.  One-line change.

Thread-safety: unchanged.  egl_init_context_common runs on the
video thread (or main thread when threaded video is off); the
configs array is a local.

Author: LibretroAdmin

gfx/common/egl_common.c

@@ -581,6 +581,7 @@ bool egl_init_context_common(
             configs, *count, &matched) || !matched)
    {
       RARCH_ERR("[EGL] No EGL configs with appropriate attributes.\n");
+      free(configs);
       return false;
    }