fix the mangled function strcmp

Fix the mangled function strcmp so that it compares all of the string
except for the numbered parts.  foo.isra.35 should match foo.isra.1, but
not foo.isra.35.part.36.

Fixes #352.
add other users of kpatch_mangled_strcmp
Merge pull request #415 from jpoimboe/mangled-strcmp

fix the mangled function strcmp