rs6000: Modify test case after mode promotion disabled

gcc/testsuite/
	PR target/102146
	* gcc.target/powerpc/pr56605.c: Modify the match pattern for dump
	scan.

gcc/testsuite/gcc.target/powerpc/pr56605.c

@@ -11,5 +11,4 @@ void foo (short* __restrict sb, int* __restrict ia)
     ia[i] = (int) sb[i];
 }
 
-/* { dg-final { scan-rtl-dump-times {\(compare:CC \((?:and|zero_extend):(?:[SD]I) \((?:sub)?reg:[SD]I} 1 "combine" } } */
-
+/* { dg-final { scan-rtl-dump-times {\(compare:CC \(and:SI \(subreg:SI \(reg:DI} 1 "combine" } } */