All callers of malloc should already do error checking, and may even be able
to continue without the alloc succeeding.

Moreover, common/malloc_simple.c is the only user of .rodata.str1.1 in
common/built-in.o when building the SPL, triggering this gcc bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54303



Causing .rodata to grow with e.g. 0xc21 bytes, nullifying all benefits of
using malloc_simple in the first place.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Simon Glass <sjg@chromium.org>