alpha: kill unnecessary __used attribute in PER_CPU_ATTRIBUTES

With the previous percpu variable definition change, all percpu
variables are global and there's no need to specify __used, which only
triggers on recent compilers anyway.  Kill it.

[ Impact: remove unnecessary percpu attribute ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>

arch/alpha/include/asm/percpu.h

@@ -30,7 +30,6 @@ extern unsigned long __per_cpu_offset[NR_CPUS];
 
 #ifndef MODULE
 #define SHIFT_PERCPU_PTR(var, offset) RELOC_HIDE(&per_cpu_var(var), (offset))
-#define PER_CPU_ATTRIBUTES
 #else
 /*
  * To calculate addresses of locally defined variables, GCC uses 32-bit
@@ -49,8 +48,6 @@ extern unsigned long __per_cpu_offset[NR_CPUS];
 		: "=&r"(__ptr), "=&r"(tmp_gp));		\
 	(typeof(&per_cpu_var(var)))(__ptr + (offset)); })
 
-#define PER_CPU_ATTRIBUTES	__used
-
 #endif /* MODULE */
 
 /*
@@ -71,8 +68,6 @@ extern unsigned long __per_cpu_offset[NR_CPUS];
 #define __get_cpu_var(var)		per_cpu_var(var)
 #define __raw_get_cpu_var(var)		per_cpu_var(var)
 
-#define PER_CPU_ATTRIBUTES
-
 #endif /* SMP */
 
 #ifdef CONFIG_SMP