[ALSA] Fix the wrong sign of format data entries

PCM Midlevel
Fix suggested by Benjamin Herrenschmidt <benh@kernel.crashing.org>

On architectures like PPC, char is handled as 'unsigned char', thus the
pcm_format_data table entries with -1 give a positive 255.  This causes
Oops with OSS-emulation on such architectures.

The patch simply adds the right signed/unsigned prefix to fix this problem.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/pcm_misc.c

@@ -25,11 +25,14 @@
 #include <sound/pcm.h>
 #define SND_PCM_FORMAT_UNKNOWN (-1)
 
+/* NOTE: "signed" prefix must be given below since the default char is
+ *       unsigned on some architectures!
+ */
 struct pcm_format_data {
-	char width;	/* bit width */
-	char phys;	/* physical bit width */
-	char le;	/* 0 = big-endian, 1 = little-endian, -1 = others */
-	char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
+	unsigned char width;	/* bit width */
+	unsigned char phys;	/* physical bit width */
+	signed char le;	/* 0 = big-endian, 1 = little-endian, -1 = others */
+	signed char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
 	unsigned char silence[8];	/* silence data to fill */
 };