checkasm/aarch64: fix tests returning a float

Avoids overriding the v0 register (which containins the result of the
tested function) in checkasm_call_checked.

tests/checkasm/aarch64/checkasm.S

@@ -112,10 +112,10 @@ function checkasm_checked_call, export=1
     movi        v3.8h,  #0
 
 .macro check_reg_neon reg1, reg2
-    ldr         q0,  [x9], #16
-    uzp1        v1.2d,  v\reg1\().2d, v\reg2\().2d
-    eor         v0.16b, v0.16b, v1.16b
-    orr         v3.16b, v3.16b, v0.16b
+    ldr         q1,  [x9], #16
+    uzp1        v2.2d,  v\reg1\().2d, v\reg2\().2d
+    eor         v1.16b, v1.16b, v2.16b
+    orr         v3.16b, v3.16b, v1.16b
 .endm
     check_reg_neon  8,  9
     check_reg_neon  10, 11