change labels from global to local in functions, align function calls in stack

srcs/ft_strlen.s

@@ -3,22 +3,22 @@ section .text
 
 ft_strlen:
 	test rdi, rdi
-	jz err
+	jz .err
 	mov rsi, rdi
-	jmp loop_start
+	jmp .loop_start
 
-increase_pointer:
+.increase_pointer:
 	lea rsi, [rsi + 1]
 
-loop_start:
+.loop_start:
 	mov al, [rsi]
 	test al, al
-	jnz increase_pointer
-end:
+	jnz .increase_pointer
+.end:
 	sub rsi, rdi 
 	mov rax, rsi
 	ret
 
-err:
+.err:
 	xor rax, rax
 	ret