bug#14501: dependency generation FAIL in t/subobj11a.sh

[Peter Rosin]

Hi!

On Automake master (baf8a1c22acce0908), t/subobj11a.sh fails
on MSYS/MSVC (depmode=msvc7msys), like this:

+ make quux
src/.deps/foo.Po:1: *** target pattern contains no `%'.  Stop.


It appears that the generated foo.Po is broken. Adding a
        cat "$depdir"/foo.Po
just before the $MAKE quux invocation reveals that the originally
generated foo.Po has this single line content:

src/foo.obj : \

Notice the trailing backslash. When the testcase then adds a
line of its own, the trailing backslash makes it blow up.

Cheers,
Peter