Fix declaration of input arguments in the x86_64 microkernels for DOT and AXPY (#1965)

* Tag operands 0 and 1 as both input and output

For #1964 (basically a continuation of coding problems first seen in #1292)

kernel/x86_64/caxpy_microk_sandy-2.c

@@ -95,10 +95,10 @@ static void caxpy_kernel_8( BLASLONG n, FLOAT *x, FLOAT *y, FLOAT *alpha)
 	"jnz		1b		             \n\t"
 	"vzeroupper					    \n\t"
 
-	:
-        : 
-          "r" (i),	// 0	
-	  "r" (n),  	// 1
+	: 
+          "+r" (i),	// 0	
+	  "+r" (n)  	// 1
+        :
           "r" (x),      // 2
           "r" (y),      // 3
           "r" (alpha),  // 4