checkpatch: fix handling of leading spaces

I've got a false positive when spaces are present at the beginning of a
line.

So I add this check, obviously excluding to check the lines in the middle of
comments.

For instance this code passes the checkpatch test:

+struct davinci_mcbsp_data {
+       unsigned int    fmt;
+    int             clk_div;
+};
+
+static struct davinci_mcbsp_data mcbsp_data;

Where, before the string "int             clk_div", I have 4 spaces (\040
ascii character).

With v2.6.34 scripts/checkpatch.pl script I get:

scripts/checkpatch.pl 0001-ASoC-DaVinci-Added-support-for-stereo-I2S.patch
total: 0 errors, 0 warnings, 201 lines checked
0001-ASoC-DaVinci-Added-support-for-stereo-I2S.patch has no obvious style
problems and is ready for submission.

That is not correct.  Instead with the proposed patch I get:

scripts/checkpatch.pl 0001-ASoC-DaVinci-Added-support-for-stereo-I2S.patch
WARNING: please, no space for starting a line,
                excluding comments
#63: FILE: sound/soc/davinci/davinci-i2s.c:165:
+    int             clk_div;$

WARNING: please, no space for starting a line,
                excluding comments
#95: FILE: sound/soc/davinci/davinci-i2s.c:406:
+    return 0;$

total: 0 errors, 2 warnings, 201 lines checked

That is correct.

Signed-off-by: Raffaele Recalcati <raffaele.recalcati@bticino.it>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>