IO Gergboard compile fix

otherio/lib/rt/src/os_linux/rt_io_gb_common.c

@@ -158,7 +158,7 @@ void setup_io()
    else
      clk_mem = clk_mem_orig;
 
-   clk_map = (unsigned char *)mmap(
+   clk_map = (char *)mmap(
       (caddr_t)clk_mem,
       BLOCK_SIZE,
       PROT_READ|PROT_WRITE,
@@ -187,7 +187,7 @@ void setup_io()
    else
      gpio_mem = gpio_mem_orig;
 
-   gpio_map = (unsigned char *)mmap(
+   gpio_map = (char *)mmap(
       (caddr_t)gpio_mem,
       BLOCK_SIZE,
       PROT_READ|PROT_WRITE,
@@ -215,7 +215,7 @@ void setup_io()
    else
      pwm_mem = pwm_mem_orig;
 
-   pwm_map = (unsigned char *)mmap(
+   pwm_map = (char *)mmap(
       (caddr_t)pwm_mem,
       BLOCK_SIZE,
       PROT_READ|PROT_WRITE,
@@ -243,7 +243,7 @@ void setup_io()
    else
      spi0_mem = spi0_mem_orig;
 
-   spi0_map = (unsigned char *)mmap(
+   spi0_map = (char *)mmap(
       (caddr_t)spi0_mem,
       BLOCK_SIZE,
       PROT_READ|PROT_WRITE,
@@ -271,7 +271,7 @@ void setup_io()
    else
      uart_mem = uart_mem_orig;
 
-   uart_map = (unsigned char *)mmap(
+   uart_map = (char *)mmap(
       (caddr_t)uart_mem,
       BLOCK_SIZE,
       PROT_READ|PROT_WRITE,

otherio/lib/rt/src/os_linux/rt_io_gb_spi.c

@@ -56,8 +56,8 @@ void setup_spi()
 // datasheet of the AD chip (MCP3002)
 //
 int read_adc(int chan) // 'chan' must be 0 or 1. This is not checked!
-{ unsigned char v1,v2,rec_c;
-  int status,w;
+{ unsigned char v1,v2;
+  int status;
   // Set up for single ended, MS comes out first
   v1 = 0xD0 | (chan<<5);
   // Delay to make sure chip select is high for a short while