parisc: Use parentheses around expression in floppy.h

David Binderman reported a style issue in the floppy.h header file:
arch/parisc/include/asm/floppy.h:221: (style) Boolean result is used in bitwise
  operation. Clarify expression with parentheses.
Reported-by: NDavid Binderman <dcb314@hotmail.com>
Cc: David Binderman <dcb314@hotmail.com>
Signed-off-by: NHelge Deller <deller@gmx.de>

arch/parisc/include/asm/floppy.h

@@ -33,7 +33,7 @@
  * floppy accesses go through the track buffer.
  */
 #define _CROSS_64KB(a,s,vdma) \
-(!vdma && ((unsigned long)(a)/K_64 != ((unsigned long)(a) + (s) - 1) / K_64))
+(!(vdma) && ((unsigned long)(a)/K_64 != ((unsigned long)(a) + (s) - 1) / K_64))
 
 #define CROSS_64KB(a,s) _CROSS_64KB(a,s,use_virtual_dma & 1)