gen_init_cpio: remove leading `/' from file names

When we extracted the generated cpio archive using "cpio -id" command,
it complained,

cpio: Removing leading `/' from member names
var/run
cpio: Removing leading `/' from member names
var/lib
cpio: Removing leading `/' from member names
var/lib/misc

It is worse with the latest "cpio" or "pax", which tries to overwrite
the host file system with the leading '/'.

So the leading '/' of file names should be removed. This is consistent
with the initramfs come with major distributions such as Fedora or
Debian, etc.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Mike Frysinger<vapier@gentoo.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

usr/gen_init_cpio.c

@@ -104,6 +104,8 @@ static int cpio_mkslink(const char *name, const char *target,
 	char s[256];
 	time_t mtime = time(NULL);
 
+	if (name[0] == '/')
+		name++;
 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 	       "%08X%08X%08X%08X%08X%08X%08X",
 		"070701",		/* magic */
@@ -152,6 +154,8 @@ static int cpio_mkgeneric(const char *name, unsigned int mode,
 	char s[256];
 	time_t mtime = time(NULL);
 
+	if (name[0] == '/')
+		name++;
 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 	       "%08X%08X%08X%08X%08X%08X%08X",
 		"070701",		/* magic */
@@ -245,6 +249,8 @@ static int cpio_mknod(const char *name, unsigned int mode,
 	else
 		mode |= S_IFCHR;
 
+	if (name[0] == '/')
+		name++;
 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 	       "%08X%08X%08X%08X%08X%08X%08X",
 		"070701",		/* magic */
@@ -332,6 +338,8 @@ static int cpio_mkfile(const char *name, const char *location,
 		/* data goes on last link */
 		if (i == nlinks) size = buf.st_size;
 
+		if (name[0] == '/')
+			name++;
 		namesize = strlen(name) + 1;
 		sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 		       "%08lX%08X%08X%08X%08X%08X%08X",