pkgdep/common: Fix liburing's .so lookup

liburing.so is a link to actual lib created under /lib, not
/usr/lib{,64}.

Instead of checking hardcoded paths, simply check the ld cache.

Change-Id: I65954490d0b79e17de791d8045a1758cbbb381f5
Signed-off-by: Michal Berger <michalx.berger@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/4020
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Karol Latecki <karol.latecki@intel.com>

scripts/pkgdep/common.sh

@@ -4,7 +4,7 @@ install_liburing() {
 	local GIT_REPO_LIBURING=https://github.com/axboe/liburing.git
 	local liburing_dir=/usr/local/src/liburing
 
-	if [[ -e /usr/lib64/liburing.so ]]; then
+	if [[ $(ldconfig -p) == *liburing.so* ]]; then
 		echo "liburing is already installed. skipping"
 	else
 		if [[ -d $liburing_dir ]]; then