S/390: s390.opt: Add period to -mzvector option text.

gcc/ChangeLog:

2016-01-15  Dominik Vogt  <vogt@linux.vnet.ibm.com>

	* config/s390/s390.opt: Add period to -mzvector option text.

From-SVN: r232417

gcc/ChangeLog

+2016-01-15  Dominik Vogt  <vogt@linux.vnet.ibm.com>
+
+	* config/s390/s390.opt: Add period to -mzvector option text.
+
 2016-01-15  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/68961

gcc/config/s390/s390.opt

@@ -176,7 +176,7 @@ mvcle use.
 mzvector
 Target Report Mask(ZVECTOR) Save
 Enable the z vector language extension providing the context-sensitive
-vector macro and enable the Altivec-style builtins in vecintrin.h
+vector macro and enable the Altivec-style builtins in vecintrin.h.
 
 mwarn-dynamicstack
 Target Var(s390_warn_dynamicstack_p) Save