lz4frame : removed some intermediate stage from LZ4F_decompress()
lz4frame : removed some intermediate stage from LZ4F_decompress()

ensure some strange jump cases are not possible
(they were already not possible, but static analyzer couldn't understand it).

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso