testsuite: Fix up gcc.target/powerpc/pr93122.c test

The recent renaming of PowerPC -mprefixed-addr option to -mprefixed
has not adjusted the gcc.target/powerpc/pr93122.c test, so it now
FAIL: gcc.target/powerpc/pr93122.c (test for excess errors)
Excess errors:
xgcc: error: unrecognized command-line option '-mprefixed-addr'; did you mean '-mprefixed'?

2020-02-12  Jakub Jelinek  <jakub@redhat.com>

	* gcc.target/powerpc/pr93122.c: Use -mprefixed instead of
	-mprefixed-addr in dg-options.

gcc/testsuite/ChangeLog

 2020-02-12  Jakub Jelinek  <jakub@redhat.com>
 
+	* gcc.target/powerpc/pr93122.c: Use -mprefixed instead of
+	-mprefixed-addr in dg-options.
+
 	PR middle-end/93663
 	* gcc.dg/torture/builtin-round-roundeven.c (main): Add tests
 	for DBL_MAX, inf, their negations and nan.

gcc/testsuite/gcc.target/powerpc/pr93122.c

 /* PR target/93122 */
 /* { dg-do compile { target lp64 } } */
-/* { dg-options "-fstack-clash-protection -mprefixed-addr -mfuture" } */
+/* { dg-options "-fstack-clash-protection -mprefixed -mfuture" } */
 
 void bar (char *);