S390: Use ahi instead of aghi in 32bit _dl_runtime_resolve.

This patch uses ahi instead of aghi in 32bit _dl_runtime_resolve
to adjust the stack pointer. This is no functional change,
but a cosmetic one.

ChangeLog:

	* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_resolve):
	Use ahi instead of aghi to adjust stack pointer.