[PATCH] alpha spinlock code and bogus constraints

"=m" (lock->lock) / "1" (lock->lock) makes gcc4 unhappy; fixed by s/1/m/,
same as in case of i386 rwsem.h where such variant had been accepted
by both Linus and rth.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>