"unknown flag" -> "unknown option"

This is an anal-retentive change :-) We prefer "uknown option" over
"unknown flag".

Author: krader1961

src/cmd/ksh93/tests/b_grep.sh

@@ -36,7 +36,7 @@ function grep
             -b*)    print 'b option not supported';;
             -e*)    shift;expr="$1";;
             -f*)    shift;expr=$(< $1);;
-            -*)    print $0: 'unknown flag';return 2;;
+            -*)     print "$0: unknown option"; return 2;;
             *)
                 if test "$expr" = ''
                 then

src/cmd/ksh93/tests/b_uname.sh

@@ -2,7 +2,7 @@
 
 # ==========
 # uname -x
-# Verify an unknown flag is handled as a usage error.
+# Verify an unknown option is handled as a usage error.
 actual=$(uname -x 2>&1)
 expect="uname: -x: unknown option"
 [[ "$actual" =~ "$expect".* ]] || log_error "uname -x" "$expect" "$actual"