[libcpu/arm]: fix typo

libcpu/arm/cortex-m0/context_gcc.S

@@ -90,7 +90,7 @@ PendSV_Handler:
     LDR     R0, =rt_thread_switch_interrupt_flag
     LDR     R1, [R0]
     CMP     R1, #0x00
-    BEQ     pendsv_exit     /* pendsv aLReady handled */
+    BEQ     pendsv_exit     /* pendsv already handled */
 
     /* clear rt_thread_switch_interrupt_flag to 0 */
     MOVS    R1, #0

libcpu/arm/cortex-m23/context_gcc.S

@@ -91,7 +91,7 @@ PendSV_Handler:
     LDR     R0, =rt_thread_switch_interrupt_flag
     LDR     R1, [R0]
     CMP     R1, #0x00
-    BEQ     pendsv_exit     /* pendsv aLReady handled */
+    BEQ     pendsv_exit     /* pendsv already handled */
 
     /* clear rt_thread_switch_interrupt_flag to 0 */
     MOVS    R1, #0

libcpu/arm/cortex-m3/context_gcc.S

@@ -90,7 +90,7 @@ PendSV_Handler:
     /* get rt_thread_switch_interrupt_flag */
     LDR     R0, =rt_thread_switch_interrupt_flag
     LDR     R1, [R0]
-    CBZ     R1, pendsv_exit         /* pendsv aLReady handled */
+    CBZ     R1, pendsv_exit         /* pendsv already handled */
 
     /* clear rt_thread_switch_interrupt_flag to 0 */
     MOV     R1, #0