fastboot: correctly set dependency on f2fs dynamic lib

In the past it would incorrectly also link against the dlopen()'d lib.

Now it clearly does not care about it.

ldd $(which fastboot)
        linux-gate.so.1 =>  (0xf7735000)
        libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xf76d9000)
        libstdc++.so.6 => /usr/lib/i386-linux-gnu/libstdc++.so.6 (0xf75f4000)
        libm.so.6 => /lib/i386-linux-gnu/libm.so.6 (0xf75c7000)
        libgcc_s.so.1 => /lib/i386-linux-gnu/libgcc_s.so.1 (0xf75a9000)
        libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xf73ff000)
        /lib/ld-linux.so.2 (0xf7736000)

Bug: 15717498
Change-Id: I5465e97a445b17f5493a1f590e181ef98a382451
Signed-off-by: JP Abgrall <jpa@google.com>