initrd.scripts: improve findnfsmount(), simplify code and branches

defaults/initrd.scripts

@@ -404,18 +404,18 @@ mount_sysfs() {
 findnfsmount() {
     if [ -z "${IP}" ]; then
         # IP is not set, return straight away
-        return 0
+        return 1
     fi
 
     if ! busybox udhcpc -n -T 15 -q; then
         bad_msg "udhcpc returned error, skipping nfs setup..."
-        return 0
+        return 1
     fi
 
     local options=
 
     [ -e /rootpath ] && NFSROOT=$(cat /rootpath)
-    if [ "${NFSROOT}" = "" ]; then
+    if [ -z "${NFSROOT}" ]; then
         # Obtain NFSIP
         # TODO: this is bogus, because dmesg is a circular buffer...
         # TODO: provide dmesg as symlink (see gen_initramfs.sh)
@@ -443,15 +443,16 @@ findnfsmount() {
         done
 
         # Setup NFSROOT
-        if [ "${NFSIP}" != "" ] && [ "$NFSPATH" != "" ]; then
+        if [ -n "${NFSIP}" ] && [ -n "$NFSPATH" ]; then
             NFSROOT="${NFSIP}:${NFSPATH}"
         else
             bad_msg "The DHCP Server did not send a valid root-path."
             bad_msg "Please check your DHCP setup, or set nfsroot=<...>"
+            return 1
         fi
     fi
 
-    if [ "${NFSROOT}" != "" ]; then
+    # expecting a valid NFSROOT here, or the code should have returned
     NFSOPTIONS=${NFSROOT#*,}
     NFSROOT=${NFSROOT%%,*}
     if [ "${NFSOPTIONS}" = "${NFSROOT}" ]; then
@@ -474,9 +475,10 @@ findnfsmount() {
     mount -t nfs -o ${NFSOPTIONS} "${NFSROOT}" "${path}"
     if [ "${?}" = "0" ]; then
         REAL_ROOT="/dev/nfs"
+        return 0
     else
         bad_msg "NFS Mounting failed. Is the path corrent ?"
-        fi
+        return 1
     fi
 }