completion: simplify inner 'case' pattern in __gitcomp()

The second '*' in the '--*=*' pattern of the inner 'case' statement of
the __gitcomp() helper function never matches anything, so let's use
'--*=' instead.

The purpose of that inner case statement is to decide when to append a
trailing space to the listed options and when not.  When an option
requires a stuck argument, i.e. '--option=', then the trailing space
should not be added, so the user can continue typing the required
argument right away.  That '--*=*' pattern is supposed to match these
options, but for this purpose that second '*' is unnecessary, a '--*='
pattern works just as well.  That second '*' would only make a
difference in case of a possible completion word like
'--option=value', but our completion script never passes such a word
to __gitcomp(), because the '--option=' and its 'value' must be
completed separately.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -340,7 +340,7 @@ __gitcomp ()
 			c="$c${4-}"
 			if [[ $c == "$cur_"* ]]; then
 				case $c in
-				--*=*|*.) ;;
+				--*=|*.) ;;
 				*) c="$c " ;;
 				esac
 				COMPREPLY[i++]="${2-}$c"
@@ -360,7 +360,7 @@ __gitcomp ()
 			c="$c${4-}"
 			if [[ $c == "$cur_"* ]]; then
 				case $c in
-				--*=*|*.) ;;
+				--*=|*.) ;;
 				*) c="$c " ;;
 				esac
 				COMPREPLY[i++]="${2-}$c"