ia64, processor: fix -Wincompatible-pointer-types in ia64_get_irr()

test_bit(), as any other bitmap op, takes `unsigned long *` as a
second argument (pointer to the actual bitmap), as any bitmap
itself is an array of unsigned longs. However, the ia64_get_irr()
code passes a ref to `u64` as a second argument.
This works with the ia64 bitops implementation due to that they
have `void *` as the second argument and then cast it later on.
This works with the bitmap API itself due to that `unsigned long`
has the same size on ia64 as `u64` (`unsigned long long`), but
from the compiler PoV those two are different.
Define @irr as `unsigned long` to fix that. That implies no
functional changes. Has been hidden for 16 years!

Fixes: a5878691 ("[IA64] avoid broken SAL_CACHE_FLUSH implementations")
Cc: stable@vger.kernel.org # 2.6.16+
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

arch/ia64/include/asm/processor.h

@@ -538,7 +538,7 @@ ia64_get_irr(unsigned int vector)
 {
 	unsigned int reg = vector / 64;
 	unsigned int bit = vector % 64;
-	u64 irr;
+	unsigned long irr;
 
 	switch (reg) {
 	case 0: irr = ia64_getreg(_IA64_REG_CR_IRR0); break;