x86/umip: Make umip_insns static

Fix the following sparse warning:
  arch/x86/kernel/umip.c:84:12: warning: symbol 'umip_insns' was not declared.
  Should it be static?
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NRicardo Neri <ricardo.neri-calderon@linux.intel.com>
Link: https://lkml.kernel.org/r/20200413082213.22934-1-yanaijie@huawei.com

arch/x86/kernel/umip.c

@@ -81,7 +81,7 @@
 #define	UMIP_INST_SLDT  3       /* 0F 00 /0 */
 #define	UMIP_INST_STR   4       /* 0F 00 /1 */
 
-const char * const umip_insns[5] = {
+static const char * const umip_insns[5] = {
 	[UMIP_INST_SGDT] = "SGDT",
 	[UMIP_INST_SIDT] = "SIDT",
 	[UMIP_INST_SMSW] = "SMSW",