improve 8042 status defines

boot1.s

@@ -645,7 +645,7 @@ intel_8042_wait_write:
   ; Read the 8042 status register.
   in al, INTEL_8042_IN_STATUS
   ; Input buffer status flag set means the input buffer is full, so loop in this case.
-  test al, (1 << INTEL_8042_STATUS_IBUF)
+  test al, INTEL_8042_STATUS_MASK_IBUF
   jnz .loop
   ret
 
@@ -659,7 +659,7 @@ intel_8042_wait_read:
   ; Read the 8042 status register.
   in al, INTEL_8042_IN_STATUS
   ; Output buffer status flag unset means output buffer is empty, so loop in this case.
-  test al, (1 << INTEL_8042_STATUS_OBUF)
+  test al, INTEL_8042_STATUS_MASK_OBUF
   jz .loop
   ret