Fixed a bug in the code for reading suppression files: the line numbers

Fixed a bug in the code for reading suppression files: the line numbers
reported in error messages were not correct. As an example, the following
output was produced before this patch (not correct):
$ ./vg-in-place --tool=helgrind --num-callers=1 /bin/true
...
FATAL: in suppressions file ".in_place/default.supp" near line 893:
   suppression must contain at least one location line which is not "..."
exiting now.
$ ./vg-in-place --tool=drd --num-callers=1 /bin/true
FATAL: in suppressions file ".in_place/default.supp" near line 475:
   suppression must contain at least one location line which is not "..."
exiting now.

After having applied this patch the above commands display line numbers
1104 and 619, referring to the first suppression pattern containing
three dots for the topmost stack frame, as expected.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10632