pgsql: Fix a couple of places where the result of fgets() wasn't

Log Message:
-----------
Fix a couple of places where the result of fgets() wasn't checked.
This is mostly to suppress compiler warnings, although in principle
the cases could result in undesirable behavior.

Martin Pitt

Modified Files:
--------------
    pgsql/src/bin/psql:
        prompt.c (r1.53 -> r1.54)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/prompt.c?r1=1.53&r2=1.54)
    pgsql/src/interfaces/libpq:
        fe-connect.c (r1.391 -> r1.392)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/libpq/fe-connect.c?r1=1.391&r2=1.392)