What this means is that the JZ instruction at offset 4 and the JMP
instruction at offset 8 both have unresolved relocations against them.
At link time the linker will resolve the relocations and store the
correct values into the instructions.
The reason why the assembler generates these relocations, rather than
just resolving the jumps directly is because the linker also performs
"relaxations" where it can replace some instructions with shorter
versions. So it is possible that the distance between a jump
instruction and its destination label will change at link time. Hence
the assembler cannot know for sure exactly what value to put into the
offset field, and hence it must use a relocation instead.