This commit fixes a memory corruption bug when parsing lines of the
form:

-x FOO=bar

The code was making changes to the size of the buffer allocated for
key_buffer without making the appropriate changes to
key_buffer_len. This was causing subsequent calls to save_param_name
to write to invalid memory.

This commit makes the following changes:

  - Fix the above bug by modifying trim_name to move the string within
    the buffer instead of re-allocating space for the trimmed string.

  - Cleaned up both trim_name and save_param_name. Both functions took
    a prefix and suffix to trim. Problem was the prefix was not
    treated like a prefix. Instead the "prefix" was located inside the
    string using strstr then the trimmed value started after the
    substring (even in the middle of the string). To allow trimming
    both -x and --x (as well as -mca and --mca) trim_name is now
    called with each prefix.

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>

(cherry picked from commit open-mpi/ompi@3223673)

Fixes open-mpi/ompi#1375

Signed-off-by: Nathan Hjelm <hjelmn@me.com>

This commit fixes a bug in the opal key value parser that might cause
the filename parser to go past the beginning of the string.

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>

(cherry picked from open-mpi/ompi@63bac9a)

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>

(cherry picked from open-mpi/ompi@607be72)

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>