{bp-19839} tools/mkversion: Fix missing free in case of error.

[jerpelea]

Summary

• According to strdup(3) manual strdup() allocates memory with malloc(3) and that memory should be released with free(3) when no longer needed.
• For non existent path or file open error mkversion used exit() with no prior free() for allocated memory.
• This change introduces ret variable, exit label, and free on exit in order to avoid potential memory leak.
• tools/mkversion is a tiny short-lived utility and the memory gets freed by the OS upon application termination so that was not a bit issue, but now memory leak scanners should be happy as we have free() in pair to strdup().

Impact

RELEASE

Testing

CI

[jerpelea]

compiled locally without error
Create version.h
LN: platform/board to /apps/platform/dummy
Register: hello
Register: nsh
Register: sh
LD: nuttx
Memory region Used Size Region Size %age Used
flash: 145148 B 16 MB 0.87%
ilm: 0 GB 128 KB 0.00%
dlm: 11360 B 128 KB 8.67%
axi_sram: 0 GB 256 KB 0.00%
axi_sram_noncacheable: 0 GB 256 KB 0.00%
ahb_sram: 0 GB 32 KB 0.00%
CP: nuttx.hex