infinite loop in ia64_mca_wakeup_ipi_wait

This bugfix has been hiding inside the MCA TLB patches.

There is an infinite loop in ia64_mca_wakeup_ipi_wait() because the compiler optimizes away the test at the bottom of the while loop. It does this because IA64_MCA_WAKEUP_VECTOR is 0xf0, so irr_bit is known to be the constant 0x30, a.k.a. 48 in decimal. So when the compiler looks at the expression:

	while (!(irr & (1 << irr_bit)))

It observes that "1" (an *integer* constant) shifted left by 48 bits is 0, and so the value of "irr" becomes irrelevent.

The fix is to make sure that the compiler treats the "1" as unsigned long:

@@ -828,7 +828,7 @@
 			irr = ia64_getreg(_IA64_REG_CR_IRR3);
 			break;
 		}
-	} while (!(irr & (1 << irr_bit))) ;
+	} while (!(irr & (1UL << irr_bit))) ;
 }
 
 /*