Remove trailing white space with:

for f in *.{h,c}; do sed -i .sed 's/[[:blank:]]*$//' $f; done
(Thanks to Nicolás Wolovick)

console.c

@@ -107,7 +107,7 @@ panic(char *s)
 {
   int i;
   uint pcs[10];
-  
+
   cli();
   cons.locking = 0;
   cprintf("cpu%d: panic: ", cpu->id);
@@ -130,7 +130,7 @@ static void
 cgaputc(int c)
 {
   int pos;
-  
+
   // Cursor position: col + 80*row.
   outb(CRTPORT, 14);
   pos = inb(CRTPORT+1) << 8;
@@ -146,13 +146,13 @@ cgaputc(int c)
 
   if(pos < 0 || pos > 25*80)
     panic("pos under/overflow");
-  
+
   if((pos/80) >= 24){  // Scroll up.
     memmove(crt, crt+80, sizeof(crt[0])*23*80);
     pos -= 80;
     memset(crt+pos, 0, sizeof(crt[0])*(24*80 - pos));
   }
-  
+
   outb(CRTPORT, 14);
   outb(CRTPORT+1, pos>>8);
   outb(CRTPORT, 15);