bpf: add _impl suffix for bpf_stream_vprintk() kfunc

Rename bpf_stream_vprintk() to bpf_stream_vprintk_impl().

This makes bpf_stream_vprintk() follow the already established "_impl"
suffix-based naming convention for kfuncs with the bpf_prog_aux
argument provided by the verifier implicitly. This convention will be
taken advantage of with the upcoming KF_IMPLICIT_ARGS feature to
preserve backwards compatibility to BPF programs.

Acked-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Mykyta Yatsenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Ihor Solodrai <[email protected]>

Author: mykyta5

docs/bpftool-prog.rst

@@ -182,7 +182,7 @@ bpftool prog tracelog
 
 bpftool prog tracelog { stdout | stderr } *PROG*
     Dump the BPF stream of the program. BPF programs can write to these streams
-    at runtime with the **bpf_stream_vprintk**\ () kfunc. The kernel may write
+    at runtime with the **bpf_stream_vprintk_impl**\ () kfunc. The kernel may write
     error messages to the standard error stream. This facility should be used
     only for debugging purposes.