Run dav1d_oss_fuzz.sh instead of dav1d.cmd to build dav1d.
dav1d_oss_fuzz.sh is a copy of dav1d.cmd, with the only difference being
that it applies a patch to the dav1d source tree to work around a bug in
Meson's symbols_have_underscore_prefix() function when oss-fuzz
specifies -fprofile-instr-generate in CFLAGS in the coverage build.
Part 2 of the fix for https://crbug.com/oss-fuzz/38512.
Wan-Teh Chang