Updated depends, bmap check update

Removed bmap-tools from depends as the check on line 96 looks for bmaptools and would use it if available if not continue to build, but have it as a depend check made the check null and if someone is on a kernel/file-system that does not support SEEK_HOLE and SEEK_DATA the script just fails.

Fixed bmap-tools check as the line which bmaptool >/dev/null 2>&1 does not return 0 so it kept ending at this line, if bmap-tools were not installed

The original code below looks for sparse to be 0 and if which bmaptool >/dev/null 2>&1 returns 0 to use bmap-tools, but I think its the reverse so swapped the last then and else sections as it would then look if sparse is 0 and which bmaptool >/dev/null 2>&1 is 0 to not use bmap-tools, but if it is 1 to use bmap-tools. If tool is available = 1 use bmap-tools, if tools is unavailable=0 do not use bmap-tools:

if [ "${OPT_SPARSE}" -eq 0 ];
  then
    which bmaptool >/dev/null 2>&1
    if [ $? -eq 0 ];
    then
      echo "[+] Defaulting to sparse image generation as bmaptool is available"
      OPT_SPARSE=1

scripts/create_sibling.sh

@@ -95,10 +95,11 @@ function setup_raspbian(){
   # Detect the ability to create sparse files
   if [ "${OPT_SPARSE}" -eq 0 ]; then
     if [ which bmaptool -eq 0 ]; then
+      echo "[!] bmaptool not available, not creating a sparse image"
+      
+    else
       echo "[+] Defaulting to sparse image generation as bmaptool is available"
       OPT_SPARSE=1
-    else
-      echo "[!] bmaptool not available, not creating a sparse image"
     fi
   fi