Various zimport.sh fixes
- $SPLSRC and $SRCDIR should be changed to $SRC_DIR. These are vestiges of an earlier version of the script and were missed when it was updated. Additionally ensure the directory is created.
- The 'fail' function should take an integer argument for the error code to return. Otherwise 0 (success) will be mistakenly returned and errors will we incorrectly suppressed. The error code should be meaningful enough to determine where the script failed.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>