Static executables don't need to free NULL pointer.

It doesn't matter really because static executable is not common scenario
but do it anyway out of pedantry.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200219185330.GA4933@avx2

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>