libgomp: testsuite: Don't XPASS libgomp.c/alloc-pinned-1.c etc. on non-Linux targets [PR113448]

Two libgomp tests XPASS on Solaris (any non-Linux target actually) since
their introduction:

XPASS: libgomp.c/alloc-pinned-1.c execution test
XPASS: libgomp.c/alloc-pinned-2.c execution test

The problem is that the test just prints

OS unsupported

and exits successfully, while the test is XFAILed:

/* { dg-xfail-run-if "Pinning not implemented on this host" { ! *-*-linux-gnu } } */

Fixed by aborting immediately after the message above in the non-Linux
case.

Tested on i386-pc-solaris2.11 and i686-pc-linux-gnu.

2024-02-02  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	libgomp:
	PR testsuite/113448
	* testsuite/libgomp.c/alloc-pinned-1.c [!__linux__] (CHECK_SIZE):
	Call abort.
	* testsuite/libgomp.c/alloc-pinned-2.c [!__linux__] (CHECK_SIZE):
	Likewise.