bpftool: Fix prog object type in manpage

bpftool's man page lists "program" as one of possible values for OBJECT,
while in fact bpftool accepts "prog" instead.
Reported-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20231103081126.170034-1-asavkov@redhat.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/bpf/bpftool/Documentation/bpftool.rst

@@ -20,7 +20,7 @@ SYNOPSIS
 
 	**bpftool** **version**
 
-	*OBJECT* := { **map** | **program** | **link** | **cgroup** | **perf** | **net** | **feature** |
+	*OBJECT* := { **map** | **prog** | **link** | **cgroup** | **perf** | **net** | **feature** |
 	**btf** | **gen** | **struct_ops** | **iter** }
 
 	*OPTIONS* := { { **-V** | **--version** } | |COMMON_OPTIONS| }