lz4: Fix out-of-bounds reads

Fix two out-of-bounds reads in lz4 decompression:

1) LZ4_decompress_generic could read one byte past the input buffer when
decoding variable length literals due to a missing bounds check. This
issue was resolved in libpayload, commonlib and cbfstool

2) ulz4fn could read up to 4 bytes past the input buffer when reading a
lz4_block_header due to a missing bounds check. This issue was resolved
in libpayload and commonlib.

Change-Id: I5afdf7e1d43ecdb06c7b288be46813c1017569fc
Signed-off-by: Alex Rebert <alexandre.rebert@gmail.com>
Found-by: Mayhem
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39174
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

payloads/libpayload/liblz4/lz4.c.inc

@@ -150,6 +150,7 @@ FORCE_INLINE int LZ4_decompress_generic(
         if ((length=(token>>ML_BITS)) == RUN_MASK)
         {
             unsigned s;
+            if ((endOnInput) && unlikely(ip>=iend-RUN_MASK)) goto _output_error;   /* overflow detection */
             do
             {
                 s = *ip++;