bpftool: fix some typos in bpftool

Hi, fix some spelling errors in bpftool, the details are as follows:

-in file "bpftool-gen.rst"
	libppf->libbpf
-in the code comments:
	ouptut->output
Signed-off-by: Lin Yikai <yikai.lin@vivo.com>
Link: https://lore.kernel.org/r/20240905110354.3274546-2-yikai.lin@vivo.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/bpf/bpftool/Documentation/bpftool-gen.rst

@@ -104,7 +104,7 @@ bpftool gen skeleton *FILE*
 
     - **example__load**.
       This function creates maps, loads and verifies BPF programs, initializes
-      global data maps. It corresponds to libppf's **bpf_object__load**\ ()
+      global data maps. It corresponds to libbpf's **bpf_object__load**\ ()
       API.
 
     - **example__open_and_load** combines **example__open** and

tools/bpf/bpftool/feature.c

@@ -196,7 +196,7 @@ static void probe_unprivileged_disabled(void)
 {
 	long res;
 
-	/* No support for C-style ouptut */
+	/* No support for C-style output */
 
 	res = read_procfs("/proc/sys/kernel/unprivileged_bpf_disabled");
 	if (json_output) {
@@ -225,7 +225,7 @@ static void probe_jit_enable(void)
 {
 	long res;
 
-	/* No support for C-style ouptut */
+	/* No support for C-style output */
 
 	res = read_procfs("/proc/sys/net/core/bpf_jit_enable");
 	if (json_output) {
@@ -255,7 +255,7 @@ static void probe_jit_harden(void)
 {
 	long res;
 
-	/* No support for C-style ouptut */
+	/* No support for C-style output */
 
 	res = read_procfs("/proc/sys/net/core/bpf_jit_harden");
 	if (json_output) {
@@ -285,7 +285,7 @@ static void probe_jit_kallsyms(void)
 {
 	long res;
 
-	/* No support for C-style ouptut */
+	/* No support for C-style output */
 
 	res = read_procfs("/proc/sys/net/core/bpf_jit_kallsyms");
 	if (json_output) {
@@ -311,7 +311,7 @@ static void probe_jit_limit(void)
 {
 	long res;
 
-	/* No support for C-style ouptut */
+	/* No support for C-style output */
 
 	res = read_procfs("/proc/sys/net/core/bpf_jit_limit");
 	if (json_output) {