arm_adi_v5: check for calloc() return value

arm_adi_v5: check for calloc() return value

In function adiv5_jim_configure() check that calloc() returns a
valid allocated memory pointer.

Change-Id: I97287e168834693900341add9d9eb9a5f38c55b4
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reported-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/7014
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>