tree-wide: convert open calls to remove spaces to skip_spaces() lib function

Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.

It decreases lib.a code size by 47 bytes and reuses the function tree-wide:
   text    data     bss     dec     hex filename
  64688     584     592   65864   10148 (TOTALS-BEFORE)
  64641     584     592   65817   10119 (TOTALS-AFTER)

Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making it redundant. In other words,
"a char equals zero is never a space".

Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below,
and found occurrences of this pattern on 3 more files:
    drivers/leds/led-class.c
    drivers/leds/ledtrig-timer.c
    drivers/video/output.c

@@
expression str;
@@

( // ignore skip_spaces cases
while (*str &&  isspace(*str)) { \(str++;\|++str;\) }
|
- *str &&
isspace(*str)
)

Signed-off-by: André Goddard Rosa <[email protected]>
Cc: Julia Lawall <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Richard Purdie <[email protected]>
Cc: Neil Brown <[email protected]>
Cc: Kyle McMartin <[email protected]>
Cc: Henrique de Moraes Holschuh <[email protected]>
Cc: David Howells <[email protected]>
Cc: <[email protected]>
Cc: Samuel Ortiz <[email protected]>
Cc: Patrick McHardy <[email protected]>
Cc: Takashi Iwai <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

net/irda/irnet/irnet.h

@@ -249,6 +249,7 @@
 #include <linux/poll.h>
 #include <linux/capability.h>
 #include <linux/ctype.h>	/* isspace() */
+#include <linux/string.h>	/* skip_spaces() */
 #include <asm/uaccess.h>
 #include <linux/init.h>
 

net/irda/irnet/irnet_ppp.c

@@ -76,9 +76,8 @@ irnet_ctrl_write(irnet_socket *	ap,
       /* Look at the next command */
       start = next;
 
-      /* Scrap whitespaces before the command */
-      while(isspace(*start))
-	start++;
+	/* Scrap whitespaces before the command */
+	start = skip_spaces(start);
 
       /* ',' is our command separator */
       next = strchr(start, ',');
@@ -133,8 +132,7 @@ irnet_ctrl_write(irnet_socket *	ap,
 	      char *	endp;
 
 	      /* Scrap whitespaces before the command */
-	      while(isspace(*begp))
-		begp++;
+	      begp = skip_spaces(begp);
 
 	      /* Convert argument to a number (last arg is the base) */
 	      addr = simple_strtoul(begp, &endp, 16);