ARM: 8584/1: floppy: avoid gcc-6 warning

gcc-6.0 warns about comparisons between two identical expressions,
which is what we get in the floppy driver when writing to the FD_DOR
register:

drivers/block/floppy.c: In function 'set_dor':
drivers/block/floppy.c:810:44: error: self-comparison always evaluates to true [-Werror=tautological-compare]
   fd_outb(newdor, FD_DOR);

It would be nice to use a static inline function instead of the
macro, to avoid the warning, but we cannot do that because the
FD_DOR definition is incomplete at this point.

Adding a cast to (u32) is a harmless way to shut up the warning,
just not very nice.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/floppy.h

@@ -17,7 +17,7 @@
 
 #define fd_outb(val,port)			\
 	do {					\
-		if ((port) == FD_DOR)		\
+		if ((port) == (u32)FD_DOR)	\
 			fd_setdor((val));	\
 		else				\
 			outb((val),(port));	\