misc: New spelling fixes in comments

compatiblity -> compatibility
continously -> continuously
existance -> existence
usefull -> useful
shoudl -> should

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

block/iscsi.c

@@ -866,7 +866,7 @@ retry:
         /* in case the get_lba_status_callout fails (i.e.
          * because the device is busy or the cmd is not
          * supported) we pretend all blocks are allocated
-         * for backwards compatiblity */
+         * for backwards compatibility */
         goto out;
     }
 

hw/ppc/spapr.c

@@ -120,7 +120,7 @@ int spapr_allocate_irq_block(int num, bool lsi, bool msi)
      * it has to be aligned to num to support multiple
      * MSI vectors. MSI-X is not affected by this.
      * The hint is used for the first IRQ, the rest should
-     * be allocated continously.
+     * be allocated continuously.
      */
     if (msi) {
         assert((num == 1) || (num == 2) || (num == 4) ||

target-alpha/translate.c

@@ -1601,7 +1601,7 @@ static ExitStatus gen_call_pal(DisasContext *ctx, int palcode)
         tcg_temp_free(pc);
 
         /* Since the destination is running in PALmode, we don't really
-           need the page permissions check.  We'll see the existance of
+           need the page permissions check.  We'll see the existence of
            the page when we create the TB, and we'll flush all TBs if
            we change the PAL base register.  */
         if (!ctx->singlestep_enabled && !(ctx->tb->cflags & CF_LAST_IO)) {

tests/test-throttle.c

@@ -18,7 +18,7 @@ LeakyBucket    bkt;
 ThrottleConfig cfg;
 ThrottleState  ts;
 
-/* usefull function */
+/* useful function */
 static bool double_cmp(double x, double y)
 {
     return fabsl(x - y) < 1e-6;
@@ -320,7 +320,7 @@ static void test_have_timer(void)
     /* zero the structure */
     memset(&ts, 0, sizeof(ts));
 
-    /* no timer set shoudl return false */
+    /* no timer set should return false */
     g_assert(!throttle_have_timer(&ts));
 
     /* init the structure */