Fixed compiler warning for enum handling

src/interfaces/ecpg/preproc/output.c

src/interfaces/ecpg/test/expected/compat_informix-rnull.c

...rfaces/ecpg/test/expected/compat_informix-test_informix.c

...faces/ecpg/test/expected/compat_informix-test_informix2.c

src/interfaces/ecpg/test/expected/connect-test2.c

src/interfaces/ecpg/test/expected/connect-test3.c

src/interfaces/ecpg/test/expected/connect-test5.c

src/interfaces/ecpg/test/expected/pgtypeslib-dt_test.c

src/interfaces/ecpg/test/expected/pgtypeslib-num_test.c

src/interfaces/ecpg/test/expected/preproc-array_of_struct.c

src/interfaces/ecpg/test/expected/preproc-autoprep.c

src/interfaces/ecpg/test/expected/preproc-define.c

src/interfaces/ecpg/test/expected/preproc-init.c

src/interfaces/ecpg/test/expected/preproc-type.c

src/interfaces/ecpg/test/expected/preproc-variable.c

src/interfaces/ecpg/test/expected/preproc-whenever.c

src/interfaces/ecpg/test/expected/sql-array.c

src/interfaces/ecpg/test/expected/sql-binary.c

src/interfaces/ecpg/test/expected/sql-code100.c

src/interfaces/ecpg/test/expected/sql-copystdout.c