Remove alignments on jump targets in memset

X86-64 memset-vec-unaligned-erms.S aligns many jump targets, which
increases code sizes, but not necessarily improve performance.  As
memset benchtest data of align vs no align on various Intel and AMD
processors

https://sourceware.org/bugzilla/attachment.cgi?id=9277

shows that aligning jump targets isn't necessary.

	[BZ #20115]
	* sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S (__memset):
	Remove alignments on jump targets.