AnyKernel2: fix patch_fstab, add replace_section

- correct typo that was breaking patch_fstab
- add function to replace entire sections of files by selecting the first and last lines of the section using search strings and replacing it entirely with a new string

anykernel.sh

@@ -108,6 +108,13 @@ replace_string() {
   fi;
 }
 
+# replace_section <file> <begin search string> <end search string> <replacement string>
+replace_section() {
+  line=`grep -n "$2" $1 | cut -d: -f1`;
+  sed -i "/${2}/,/${3}/d" $1;
+  sed -i "${line}s;^;${4}\n;" $1;
+}
+
 # insert_line <file> <if search string> <before|after> <line match string> <inserted line>
 insert_line() {
   if [ -z "$(grep "$2" $1)" ]; then
@@ -171,10 +178,10 @@ replace_file() {
   chmod $2 $1;
 }
 
-# patch_fstab <fstab file> <mount match name> <fs match type> <block|mount|fstype|options|flags> <if search string> <replacement string>
+# patch_fstab <fstab file> <mount match name> <fs match type> <block|mount|fstype|options|flags> <original string> <replacement string>
 patch_fstab() {
   entry=$(grep "$2" $1 | grep "$3");
-  if [ -z "$(echo "$entry" | grep "$5")" ]; then
+  if [ -z "$(echo "$entry" | grep "$6")" ]; then
     case $4 in
       block) part=$(echo "$entry" | awk '{ print $1 }');;
       mount) part=$(echo "$entry" | awk '{ print $2 }');;
@@ -225,7 +232,7 @@ fi;
 backup_file fstab.tuna;
 patch_fstab fstab.tuna /system ext4 options "nodiratime,barrier=0" "nodev,noatime,nodiratime,barrier=0,data=writeback,noauto_da_alloc,discard";
 patch_fstab fstab.tuna /cache ext4 options "barrier=0,nomblk_io_submit" "nosuid,nodev,noatime,nodiratime,errors=panic,barrier=0,nomblk_io_submit,data=writeback,noauto_da_alloc";
-patch_fstab fstab.tuna /userdata ext4 options "nomblk_io_submit,data=writeback" "nosuid,nodev,noatime,errors=panic,nomblk_io_submit,data=writeback,noauto_da_alloc";
+patch_fstab fstab.tuna /data ext4 options "nomblk_io_submit,data=writeback" "nosuid,nodev,noatime,errors=panic,nomblk_io_submit,data=writeback,noauto_da_alloc";
 append_file fstab.tuna "usbdisk" fstab;
 
 # end ramdisk changes