math-emu: Fix compiler warnings

Fix warnings of the form:
arch/powerpc/math-emu/fsubs.c:15: warning: 'R_f1' may be used uninitialized in this function
arch/powerpc/math-emu/fsubs.c:15: warning: 'R_f0' may be used uninitialized in this function

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

include/math-emu/op-2.h

@@ -25,7 +25,7 @@
 #ifndef __MATH_EMU_OP_2_H__
 #define __MATH_EMU_OP_2_H__
 
-#define _FP_FRAC_DECL_2(X)	_FP_W_TYPE X##_f0, X##_f1
+#define _FP_FRAC_DECL_2(X)	_FP_W_TYPE X##_f0 = 0, X##_f1 = 0
 #define _FP_FRAC_COPY_2(D,S)	(D##_f0 = S##_f0, D##_f1 = S##_f1)
 #define _FP_FRAC_SET_2(X,I)	__FP_FRAC_SET_2(X, I)
 #define _FP_FRAC_HIGH_2(X)	(X##_f1)