pseudo: Make realpath() remove trailing slashes

pseudo: Make realpath() remove trailing slashes

Linux system's realpath() remove trailing slashes, but pseudo's doesn't, need
make them identical.

E.g., the following code (rel.c) prints '/tmp' with system's realpath, but
pseudo's realpath prints '/tmp/':

    #include <stdio.h>
    #include <limits.h>
    #include <stdlib.h>

    int main() {
        char out[PATH_MAX];
        printf("%s\n", realpath("/tmp/", out));
        return 0;
    }

$ bitbake base-passwd -cdevshell # For pseudo env
$ gcc rel.c
$ ./a.out
/tmp/ (but should be /tmp)

This patch fixes the problem.

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>