pgsql: Fix incorrect "return NULL" in BumpAllocLarge().

Fix incorrect "return NULL" in BumpAllocLarge().

This must be "return MemoryContextAllocationFailure(context, size, flags)"
instead. The effect of this oversight is that if we got a malloc
failure right here, the code would act as though MCXT_ALLOC_NO_OOM
had been specified, whether it was or not. That would likely lead
to a null-pointer-dereference crash at the unsuspecting call site.

Noted while messing with a patch to improve our Valgrind leak
detection support. Back-patch to v17 where this code came in.

Branch
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REL_17_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/a05cf22e0540e55fb34e26e6e98a8a76b76d1cbd

Modified Files
--------------
src/backend/utils/mmgr/bump.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)