testdb: pass empty local pkglist to alpm_checkdeps

Passing the local package list to alpm_checkdeps as both the local
packages and packages to be upgraded did nothing but cause extra
overhead as the packages were all removed from the installed package
list because they were being upgraded.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
testdb: quote output substitutions

Quoting output substitutions makes whitespace errors such as FS#30101
much more obvious:

old:
    missing perl-test-pod  dependency for perl-test-output
new:
    missing 'perl-test-pod ' dependency for 'perl-test-output'

Several of the quoted substitutions should not be capable of containing
whitespace in theory, but this errs on the side of caution as the point
of the tool is to find error conditions.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>