common/rc, dm/003, nvme/065: move TO_SKIP to common/rc

TO_SKIP is defined as readonly at two places in dm/003 and nvme/065.
When these two test cases are run at once, bash complains that the
readonly value is assigned twice. To avoid the error, do not declare the
value as readonly. Also, move the declarations of TO_SKIP to common/rc
to avoid the duplicated declarations.

Reported-by: Yi Zhang <[email protected]>
Link: #204
Signed-off-by: Shin'ichiro Kawasaki <[email protected]>

Author: kawasaki

common/rc

@@ -14,6 +14,7 @@ shopt -s extglob
 
 declare IO_URING_DISABLED
 declare -a SYSTEMCTL_UNITS_TO_STOP
+export TO_SKIP=255
 
 # If a test runs multiple "subtests", then each subtest should typically run
 # for TIMEOUT / number of subtests.

tests/dm/003

@@ -15,8 +15,6 @@ requires() {
 	_have_scsi_debug
 }
 
-readonly TO_SKIP=255
-
 setup_test_device() {
 	local dev blk_sz dpath
 

tests/nvme/065

@@ -20,8 +20,6 @@ requires() {
 	_require_nvme_trtype_is_loop
 }
 
-readonly TO_SKIP=255
-
 setup_test_device() {
 	local port