asm: make all text section labels .L local

To help with backtraces if we ever fix them due to the lkmc_asm_main_after_prologue debacle.

userland/arch/arm/adr.S

@@ -6,14 +6,14 @@
 data_label:
     .word 0x1234678
 LKMC_PROLOGUE
-    adr r4, label
+    adr r4, .Llabel
     /* objdump tells us that this uses the literal pool,
      * it does not get converted to adr, which is the better
      * alternative here.
      */
-    ldr r5, =label
-    adrl r6, label
-label:
+    ldr r5, =.Llabel
+    adrl r6, .Llabel
+.Llabel:
     LKMC_ASSERT_EQ_REG(r4, r5)
     LKMC_ASSERT_EQ_REG(r4, r6)
 

userland/arch/arm/b.S

@@ -3,7 +3,7 @@
 #include <lkmc.h>
 LKMC_PROLOGUE
     /* Jump over the fail. 26-bit PC-relative. */
-    b ok
+    b .Lok
     LKMC_ASSERT_FAIL
-ok:
+.Lok:
 LKMC_EPILOGUE

userland/arch/arm/registers.S

@@ -48,7 +48,6 @@ LKMC_PROLOGUE
 10:
 
     /* Another example with mov reading from pc. */
-pc_addr:
     mov r0, pc
     /* Why sub 8:
      * https://stackoverflow.com/questions/24091566/why-does-the-arm-pc-register-point-to-the-instruction-after-the-next-one-to-be-e

userland/arch/arm/str.S

@@ -46,8 +46,8 @@ LKMC_PROLOGUE
      * This construct is not possible in ARMv8 for str:
      * https://github.com/cirosantilli/linux-kernel-module-cheat#armv8-aarch64-str-instruction
      */
-    str r1, var_in_same_section
-var_in_same_section:
+    str r1, .Lvar_in_same_section
+.Lvar_in_same_section:
 #endif
 
     /* = sign just doesn't make sense for str, you can't set the