x86: fix sparse error in traps_32.c

This was being used to ensure the proper alignment of the FXSAVE/FXRSTOR data.
This would create a sparse error in the _correct_ cases, hiding further
warnings.  Use BUILD_BUG_ON instead.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/traps_32.c

@@ -1176,17 +1176,12 @@ void __init trap_init(void)
 #endif
 	set_trap_gate(19,&simd_coprocessor_error);
 
-	if (cpu_has_fxsr) {
 	/*
 	 * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
-		 * Generates a compile-time "error: zero width for bit-field" if
-		 * the alignment is wrong.
+	 * Generate a build-time error if the alignment is wrong.
 	 */
-		struct fxsrAlignAssert {
-			int _:!(offsetof(struct task_struct,
-					thread.i387.fxsave) & 15);
-		};
-
+	BUILD_BUG_ON(offsetof(struct task_struct, thread.i387.fxsave) & 15);
+	if (cpu_has_fxsr) {
 		printk(KERN_INFO "Enabling fast FPU save and restore... ");
 		set_in_cr4(X86_CR4_OSFXSR);
 		printk("done.\n");