Remove print_error and use normal println in exception handlers

(cherry picked from commit 9b83b2853e)

src/interrupts/mod.rs

@@ -72,21 +72,17 @@ struct ExceptionStackFrame {
     stack_segment: u64,
 }
 
-use vga_buffer::print_error;
-
 extern "C" fn divide_by_zero_handler(stack_frame: *const ExceptionStackFrame) -> ! {
-    unsafe {
-        print_error(format_args!("EXCEPTION: DIVIDE BY ZERO\n{:#?}", *stack_frame));
-    }
+    let stack_frame = unsafe { &*stack_frame };
+    println!("\nEXCEPTION: DIVIDE BY ZERO\n{:#?}", stack_frame);
     loop {}
 }
 
 extern "C" fn invalid_opcode_handler(stack_frame: *const ExceptionStackFrame) -> ! {
-    unsafe {
-        print_error(format_args!("EXCEPTION: INVALID OPCODE at {:#x}\n{:#?}",
-                                 (*stack_frame).instruction_pointer,
-                                 *stack_frame));
-    }
+    let stack_frame = unsafe { &*stack_frame };
+    println!("\nEXCEPTION: INVALID OPCODE at {:#x}\n{:#?}",
+             stack_frame.instruction_pointer,
+             stack_frame);
     loop {}
 }
 
@@ -101,13 +97,12 @@ bitflags! {
 }
 
 extern "C" fn page_fault_handler(stack_frame: *const ExceptionStackFrame, error_code: u64) -> ! {
+    let stack_frame = unsafe { &*stack_frame };
     use x86::controlregs;
-    unsafe {
-        print_error(format_args!("EXCEPTION: PAGE FAULT while accessing {:#x}\nerror code: \
+    println!("\nEXCEPTION: PAGE FAULT while accessing {:#x}\nerror code: \
                                   {:?}\n{:#?}",
-                                 controlregs::cr2(),
+             unsafe { controlregs::cr2() },
              PageFaultErrorCode::from_bits(error_code).unwrap(),
-                                 *stack_frame));
-    }
+             stack_frame);
     loop {}
 }

src/vga_buffer.rs

@@ -43,18 +43,6 @@ pub fn clear_screen() {
     }
 }
 
-pub unsafe fn print_error(fmt: fmt::Arguments) {
-    use core::fmt::Write;
-
-    let mut writer = Writer {
-        column_position: 0,
-        color_code: ColorCode::new(Color::Red, Color::Black),
-        buffer: Unique::new(0xb8000 as *mut _),
-    };
-    writer.new_line();
-    writer.write_fmt(fmt);
-}
-
 #[allow(dead_code)]
 #[derive(Debug, Clone, Copy)]
 #[repr(u8)]