The code previously checked it's own name and called 'die' upon
an error. However 'die' was not yet defined because git-sh-setup
had not been sourced yet. Instead simply write the error message
to stderr and exit with an error as was originally desired.
Signed-off-by: Bob Proulx <bob@proulx.com> Signed-off-by: Junio C Hamano <junkio@cox.net>