[pass] Makefile not compatible with dash

[René Neumann]

Hi,

the Makefile uses [ "$(FORCE_BASHCOMP)" == "1" ] (and similar for the
other COMPs). Unfortunately, this does not work with dash (which is what
/bin/sh points to here):

/bin/sh: 1: [: unexpected operator
/bin/sh: 1: [: 1: unexpected operator
/bin/sh: 1: [: unexpected operator

I'm by no means a shell expert, but I think, POSIX has '=' as the
equality operator only. Also no argument must be empty, so it should be
more along the lines of: [ "x$(FORCE_BASHCOMP)" = "x1" ].

- René