arm: fix PIC vs SHARED typos

the logic in setjmp/__longjmp incorrectly tie to "PIC" to figure out
whether the code is going into a shared library when it should be using
"SHARED".  otherwise, building static PIC code goes wrong.

https://bugs.gentoo.org/336914
http://sourceware.org/ml/libc-ports/2011-09/msg00018.html

2011-09-19  David Lamparter  <equinox-gentoo@diac24.net>

	* sysdeps/arm/setjmp.S: Change PIC to SHARED.
	* sysdeps/arm/__longjmp.S: Likewise