Change SometimesInlineFunction to "return i * i * 3;"

Change SometimesInlineFunction to "return i * i * 3;"

The debug_msg test has 2 implementations of SometimesInlineFunction:

int SometimesInlineFunction(int i) { return i; }
int SometimesInlineFunction(int i) { return i * i; }

and One Definition Rule (ODR) violation detection expects they will be
compiled into functions of different sizes.  Hower, on x86, GCC 4.7 and
newer compile them into functions of the same size and ODR violation
detection test fails.  This patch changes

int SometimesInlineFunction(int i) { return i; }

to

int SometimesInlineFunction(int i) { return i * i * 3; }

so that it will be compiled into a function of larger size.

	PR gold/14608
	* testsuite/debug_msg.cc (SometimesInlineFunction): Changed
	to "return i * i * 3;".