x86/mtrr: Fix a kernel-doc markup

Kernel-doc markup should use this format:
	identifier - description

Fix it.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/2217cd4ae9e561da2825485eb97de77c65741489.1603469755.git.mchehab+huawei@kernel.org

arch/x86/kernel/cpu/mtrr/mtrr.c

@@ -813,7 +813,8 @@ void mtrr_ap_init(void)
 }
 
 /**
- * Save current fixed-range MTRR state of the first cpu in cpu_online_mask.
+ * mtrr_save_state - Save current fixed-range MTRR state of the first
+ *	cpu in cpu_online_mask.
  */
 void mtrr_save_state(void)
 {