perf: use GIT_PERF_REPEAT_COUNT=3 by default even without config file

9ba95ed23c (perf/run: update get_var_from_env_or_config() for
subsections) stopped setting a default value for GIT_PERF_REPEAT_COUNT
if no perf config file is present, because get_var_from_env_or_config
returns early in that case.

Fix it by setting the default value after calling this function.  Its
fifth parameter is not used for any other variable, so remove the
associated code.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/perf/run

@@ -106,7 +106,6 @@ get_var_from_env_or_config () {
 	conf_sec="$2"
 	conf_var="$3"
 	conf_opts="$4" # optional
-	# $5 can be set to a default value
 
 	# Do nothing if the env variable is already set
 	eval "test -z \"\${$env_var+x}\"" || return
@@ -122,13 +121,12 @@ get_var_from_env_or_config () {
 	fi
 	var="$conf_sec.$conf_var"
 	conf_value=$(git config $conf_opts -f "$GIT_PERF_CONFIG_FILE" "$var") &&
-	eval "$env_var=\"$conf_value\"" && return
-
-	test -n "${5+x}" && eval "$env_var=\"$5\""
+	eval "$env_var=\"$conf_value\""
 }
 
 run_subsection () {
-	get_var_from_env_or_config "GIT_PERF_REPEAT_COUNT" "perf" "repeatCount" "--int" 3
+	get_var_from_env_or_config "GIT_PERF_REPEAT_COUNT" "perf" "repeatCount" "--int"
+	: ${GIT_PERF_REPEAT_COUNT:=3}
 	export GIT_PERF_REPEAT_COUNT
 
 	get_var_from_env_or_config "GIT_PERF_DIRS_OR_REVS" "perf" "dirsOrRevs"