Comment 4 for bug 543478

Note that putting quotes around the filename lets you use '/'. I.e.
pmemsave 0x200 0x200 "/tmp/abab"

I assume this is a shortcoming in the parser, as the source code at first glance
claims to simply read a string. So I'm not sure how easily fixable it would be,
but it appears to be something for upstream to consider (whether to fix needing
to quote a filename, or add more precise help on error).