pkgdep/git: Fix git version check

f62834a6bb forgot to actually retrieve version string. Also, use
common function for comparing the strings.

Change-Id: I022ab54ea5b4edf0b596776dd35ca8637506ee46
Signed-off-by: Michal Berger <michalx.berger@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/4833
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

test/common/config/pkgdep/git

@@ -246,12 +246,9 @@ function install_libiscsi() {
 
 function install_git() {
 	if type -P git; then
-		if [[ $(sort -V) == "$GIT_VERSION"* ]]; then
-			# Our version is on top, meaning there's a newer git version installed
-			# or we already have matching one on board. Either way, we don't need
-			# to do anything, return.
+		if ge "$(git --version | awk '{print $3}')" "$GIT_VERSION"; then
 			return 0
-		fi <<< "$GIT_VERSION"$'\n'"$(git --version)"
+		fi
 	fi >/dev/null
 
 	install zlib-devel curl-devel

test/common/config/vm_setup.sh

@@ -101,6 +101,7 @@ function detect_package_manager() {
 
 vmsetupdir=$(readlink -f "$(dirname "$0")")
 rootdir=$(readlink -f "$vmsetupdir/../../../")
+source "$rootdir/scripts/common.sh"
 
 set_os_id_version
 detect_package_manager