Use consistent/modern code formatting for pointers

The convention used by libjpeg:

    type * variable;

is not very common anymore, because it looks too much like
multiplication.  Some (particularly C++ programmers) prefer to tuck the
pointer symbol against the type:

    type* variable;

to emphasize that a pointer to a type is effectively a new type.
However, this can also be confusing, since defining multiple variables
on the same line would not work properly:

    type* variable1, variable2;  /* Only variable1 is actually a
                                    pointer. */

This commit reformats the entirety of the libjpeg-turbo code base so
that it uses the same code formatting convention for pointers that the
TurboJPEG API code uses:

    type *variable1, *variable2;

This seems to be the most common convention among C programmers, and
it is the convention used by other codec libraries, such as libpng and
libtiff.

rdjpgcom.c

@@ -57,7 +57,7 @@
  * To reuse this code in another application, you might need to change these.
  */
 
-static FILE * infile;           /* input JPEG file */
+static FILE *infile;            /* input JPEG file */
 
 /* Return next input byte, or EOF if no more */
 #define NEXTBYTE()  getc(infile)
@@ -279,7 +279,7 @@ process_SOFn (int marker)
   unsigned int length;
   unsigned int image_height, image_width;
   int data_precision, num_components;
-  const char * process;
+  const char *process;
   int ci;
 
   length = read_2_bytes();      /* usual parameter length count */
@@ -397,7 +397,7 @@ scan_JPEG_header (int verbose, int raw)
 
 /* Command line parsing code */
 
-static const char * progname;   /* program name for error messages */
+static const char *progname;    /* program name for error messages */
 
 
 static void
@@ -417,7 +417,7 @@ usage (void)
 
 
 static int
-keymatch (char * arg, const char * keyword, int minchars)
+keymatch (char *arg, const char *keyword, int minchars)
 /* Case-insensitive matching of (possibly abbreviated) keyword switches. */
 /* keyword is the constant keyword (must be lower case already), */
 /* minchars is length of minimum legal abbreviation. */
@@ -449,7 +449,7 @@ int
 main (int argc, char **argv)
 {
   int argn;
-  char * arg;
+  char *arg;
   int verbose = 0, raw = 0;
 
   /* On Mac, fetch a command line. */